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1986 Tachometer wiring

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Nickelplate

1986 Tachometer wiring

I have looked at https://www.garysgaragemahal.com/tachometers.html to check this, but I haven't been able to figure out the "extra ground that changes it to 8cyl mode". Is that done somewhere inside the gauge cluster? Is it under the dash? Or is it the Black/LtGreen ground wire #60 (in connector C-323)? Or somewhere else? My Tach is consistently showing 500RPM lower than actual. I'm wondering if I need to run a ground to that wire #60. There are a lot of wires I'm no longer using after my Edelbrock Pro-Flo 4 install, and that is one that is now not connected to anything.

1986 Bronco. 5.0L, Edelbrock Pro-flo 4 EFI, Baumann-controlled 4r70w, 3.55 gears, 31" tires.

Gary Lewis

Re: 1986 Tachometer wiring

Administrator

An 8 cylinder ignition harness has that wire in it and it grounds the 8 cyl terminal on the tach. A 6 cyl harness won't have it. But, 500 RPM off consistently sounds like just an error in the tach. You can pull the needle off and put it back on 500 off.

Gary, AKA "Gary fellow": Profile

Dad's: '81 F150 Ranger XLT 4x4: Down for restomod: Full-roller "stroked 351M" w/Trick Flow heads & intake, EEC-V SEFI/E4OD/3.50 gears w/Kevlar clutches
Blue: 2015 F150 Platinum 4x4 SuperCrew wearing Blue Jeans & sporting a 3.5L EB & Max Tow
Big Blue: 1985 F250HD 4x4: 460/ZF5/3.55's, D60 w/Ox locker & 10.25 Sterling/Trutrac, Blue Top & Borgeson, & EEC-V MAF/SEFI

Nickelplate

Re: 1986 Tachometer wiring

Thanks, Gary! Helpful as always!

I will ground wire #60 and then work on my Tach.

1986 Bronco. 5.0L, Edelbrock Pro-flo 4 EFI, Baumann-controlled 4r70w, 3.55 gears, 31" tires.

mat in tn

Re: 1986 Tachometer wiring

BE CAREFUL WITH THAT NEEDLE . god they are fragile